The new HSSL protocol for communication between microcontrollers specifies extended timeout functionalities for the execution of commands. Specifically, said timeout functionalities serve to monitor the period of time from the instance in time when a corresponding command frame is sent until the instance in time when a corresponding response frame is received.
The response frame indicates a successful or erroneous execution of the corresponding command. In case the monitored period of time is exceeded, a timeout error message may be generated.
Furthermore, the HSSL protocol specifies multiple channels for commands with a fixed priority, wherein the command and response frames are transmitted over the same interface by time division multiplexing.
With regard to channel priorities, command or response frames that are transmitted over a channel with a low channel number take priority over command or response frames that are transmitted over a channel with a higher channel number. Due to the above, the execution of a command transmitted over a predetermined channel may be substantially delayed by commands transmitted over channels with a lower channel number.
Moreover, the HSSL protocol specifies pipelining for commands handling large data blocks, called stream commands, wherein multiple stream commands may be executed in parallel. Hence, the timeout functionality should provide for parallel monitoring of multiple temporally overlapping executions of stream commands.